1. Field
The present invention relates to a fuel cell, and more particularly to a reformer for a fuel cell.
2. Discussion of Related Technology
A fuel cell, which is a power generation system that directly receives electricity from hydrocarbon-based organic fuel, such as methanol, ethanol, natural gas, butane and gasoline, etc., has been spotlighted as a next generation energy source for low pollution and high efficiency.
According to sorts of electrolyte used, fuel cells can be sorted as a phosphoric acid fuel cell, a molten carbonate fuel cell, a solid oxide fuel cell, a polymer electrolyte fuel cell and an alkaline fuel cell, etc. These respective fuel cells are basically operated based on the same principle, but are different in view of sorts of fuels used, operating temperatures, catalyst and electrolytes, etc. Among others, the polymer electrolyte membrane fuel cell (PEMFC) using polymer as electrolyte, has no risk of the corrosion or evaporation by the electrolyte and obtains high current density per the unit area. Furthermore, since the polymer electrolyte membrane fuel cell (PEMFC) has advantages of a remarkably high output feature and a low operating temperature feature over other fuel cells, it has actively been developed for being applicable to a mobile power source, such as a portable electronic equipment or a transportable power source, such as a power source for automobile as well as a distributed power source, such as a stationary power plant used in a house and a public building, etc.
A fuel cell is composed of a membrane electrode assembly (MEA) in a unit cell, and electricity is generated from each unit cell. The unit cell has a structure that an anode electrode and a cathode electrode having a catalyst layer applied thereto are adhered to each other, putting an electrolyte membrane therebetween. The electrochemical reaction equation between the anode electrode and the cathode electrode is as follows:Anode electrode: 2H2→4H++4e−Cathode electrode: O2+4e−+4H+→2H2O   [Reaction Equation 1]The power generated from the unit cell is weak as about 1V or so, often causing a case that a desired power cannot be obtained with only one unit cell. Therefore, in order to obtain a desired power, a fuel cell is usually manufactured in a stack shape that a plurality of unit cells is connected in series.
The discussion in this section is to provide general background information, and does not constitute an admission of prior art.